<template>
  <div class="login-container">
    <div class="login-box">
      <!-- 头像区域 -->
      <div class="avatar-box">
        <img src="../assets/logo.png" alt="" @click="succ" />
      </div>
      <!-- 表单区域 -->
      <el-form
        ref="loginForms"
        :model="loginForm"
        :rules="loginFormRules"
        label-width="0px"
        class="login_form"
      >
        <!-- 用户名 -->
        <el-form-item prop="username">
          <el-input
            v-model="loginForm.username"
            prefix-icon="iconfont icon-user"
            @focus="check(3)"
          ></el-input>
        </el-form-item>
        <!-- 密码 -->
        <el-form-item prop="password">
          <el-input
            v-model="loginForm.password"
            prefix-icon="iconfont icon-3702mima"
            @focus="check(1)"
            @blur="check(2)"
            ref="password"
          ></el-input>
        </el-form-item>
        <!-- 按钮 -->
        <el-form-item class="btns">
          <el-button type="primary" @click="login">登录</el-button>
          <el-button type="info" @click="reset">重置</el-button>
        </el-form-item>
      </el-form>
    </div>
  </div>
</template>

<script>
export default {
  data () {
    return {
      // 登陆表单对应对象
      loginForm: {
        username: '用户名',
        password: '密码'
      },
      // 表单验证规则
      loginFormRules: {
        username: [
          { required: true, message: '请输入用户名', trigger: 'blur' },
          { min: 3, max: 5, message: '长度在 3 到 5 个字符', trigger: 'blur' }
        ],
        password: [
          { required: true, message: '请输入密码', trigger: 'blur' },
          { min: 6, max: 16, message: '长度在 6 到 16 个字符', trigger: 'blur' }
        ]
      }
    }
  },
  methods: {
    check (a) {
      if (this.loginForm.password === '密码' && a === 1) {
        this.loginForm.password = ''
        this.$refs.password.type = 'password'
      }
      if (this.loginForm.username === '用户名' && a === 3) {
        this.loginForm.username = ''
      }
    },
    reset () {
      this.$refs.loginForms.resetFields()
      this.$refs.password.type = 'text'
    },
    login () {
      this.$refs.loginForms.validate(async valid => {
        if (!valid) {
          return false
        } else {
          const { data: res } = await this.$http.post('login', this.loginForm)
          if (res.meta.status !== 200) {
            this.$message.error('登陆失败')
          } else {
            this.$message.success('登陆成功')
            // 将登陆成功后的token保存到客户端的 sessionStorage 中
            window.sessionStorage.setItem('token', res.data.token)
            //  + 项目中除了登录之外的其他API接口，必须在登陆之后才可访问
            //  + token 值应在当前网站打开期间生效，所以将token保存在 ………… 中
            // 通过编程时导航跳转到后台主页，路由地址是 /home
            this.$router.push('/home')
          }
        }
      })
    },
    succ () {
      this.loginForm.password = '123456'
      this.loginForm.username = 'admin'
    }
  }
}
</script>

<style scoped>
.login-container {
  background-color: #2b4b6b;
  height: 100%;
}
.login-box {
  width: 450px;
  height: 300px;
  background-color: #fff;
  border-radius: 3px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
.avatar-box {
  height: 130px;
  width: 130px;
  border: 1px solid #eee;
  border-radius: 50%;
  padding: 10px;
  box-shadow: 0 0 10px #ddd;
  position: absolute;
  left: 50%;
  background-color: #fff;
  transform: translate(-50%, -50%);
}
.avatar-box img {
  width: 100%;
  height: 100%;
  background-color: #eee;
  border-radius: 50%;
}
.btns {
  display: flex;
  justify-content: flex-end;
}
.login_form {
  position: absolute;
  bottom: 0;
  width: 100%;
  padding: 0 20px;
  box-sizing: border-box;
}
</style>
